HINFO record definition
An HINFO record is a type of DNS record that describes the hardware and OS characteristics of a specific host. HINFO records are largely considered obsolete due to privacy and security concerns — they are largely limited to secure internal networks to prevent exposing potentially sensitive information to outside harm.
HINFO records contain two strings: one representing the CPU type (such as “INTEL”) and the other representing the operating system (like “LINUX”). While these values are not strictly standardized, certain conventions have developed over time, such as using "VAX" for Digital Equipment Corporation machines and "UNIX" for Unix-based systems.
See also: DNS resolution, DNS, DNS redirection, DNS record, DNS query, DNS CNAME record
Dangers associated with HINFO records
When DNS was first conceived, the HINFO record was useful for administrative and operational purposes. However, as the internet expanded and security became a major concern, the use of HINFO records declined significantly — revealing hardware and operating system information in DNS records lets malicious actors identify potential targets for exploitation.
For example, by knowing the operating system of a specific server, hackers can target known vulnerabilities instead of carefully probing the network’s defenses. Because of this risk, many administrators avoid using HINFO records entirely — in fact, certain DNS server configurations block or ignore HINFO records by default.
